Method of processing edible bivalves



July 14, 1936. M. B. JENKINS METHOD OF PROCESSING EDIBLE BIVALVES s Sheets-Sheet 1 Filed May 5, 1934 Jill/672i?!" irz'am flJenkms July 14, 1936. M. B. JENKINS METHOD OF PROCESSING EDIBLE BIVALVES Filed May 5, 1934 3 Sheets-Sheet 2 64 Fig.4

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July 14,' 1936. M. B. JENKINS 2,047,688

METHOD OF PROCESSING EDIBLE BIVALVES Filed May 5, 1934 5 Sheets-Sheet 5 Patented July 14, 1936 PATENT OFFIQE METHOD OF PROCESSING EDIBLE BIVALVES Miriam B. Jenkins, Long Beach, Calif.

Application May 5, 1934, Serial No. 724,191

6 Claims.

My invention relates to sea foods, with reference especially to mollusks, and is directed to a method particularly applicable to the processing of relatively small bivalve mollusks, such as mussels, oysters, clams, and the like.

My invention is applicable to bivalves of all sizes, but, for the purposes of this disclosure, will be confined to relatively small bivalves, the particular species being Donate Zaevigate, a small clam abundant on the Pacific Coast or elsewhere. These clams, as small as one-half inch or less in maximum dimension, are found in extensive beds along sea shores, generally buried in the sands of tide lands, and constitute a vast reserve of food that has not been utilized on a commercial scale because no economical and efficient means of processing such small bivalves has heretofore been developed.

These clams from the beach sands are not uniform in shape nor size within sufficiently small limits to make ordinary mechanical separation of the meats from the shells practical, especially because the shells are fragile and tend, when; crushed, to become inseparably imbedded in the meats. Individual handling of the bivalves, as an alternative procedure, is impractical because of the prohibitive labor costs involved.

The general purpose of my invention is to provide a practical process for the commercial exploitation of these natural resources.

In its broader aspects, the process comprises cooking the bivalves to open the shells, stirring 01' tumbling the cooked product to disjoin the meats, and finally, separating the meats from the shells by flotation. Preferably, the cooking operation consists of boiling or steaming, and the resultant broth is drawn off to be added later to the isolated meats.

At the heart of the invention is my discovery that agitation or tumbling of the opened bivalves in mass causes the shells of some bivalves to serve as instruments for disjoining meats from other contiguous bivalves; and my invention provides a practical process based upon this discovery.

Other objects and advantages of my process Will be best understood by reference to the de tailed description, to follow.

In the drawings that supplement my description:

Fig. 1, and Fig. 2 in continuation thereof, represent a longitudinal medial section through my apparatus as designed for continuous production on a large scale, certain parts being shown in elevation;

Fig. 3 is an enlarged transverse section through the rotary cooker, taken as indicated by the line 33 of Fig. 2;

Fig. 4 is an enlarged fragmentary, horizontal section of the cooker, taken as indicated by the line 4-4 of Fig. 2; 5

Fig. 5 is an enlarged vertical transverse section through the tumbler, taken as indicated by the line 5--5 of Fig. 2;

Fig. 6 is an enlarged vertical transverse section through the separator, taken as indicated by the 10 line 66 of Fig. 2;

Fig. 7 is an enlarged plan View of the separator, taken partly in section, as indicated by the line 'l! of Fig. 2;

Fig. 8 is an enlarged end View of a clam as it is 15 takenfrom the beach;

Fig. 9 is an enlarged end view of a clam opened by the cooking process;

Fig. 10 is a similar view on a smaller scale, to

indicate how, when the opened clams are agi- 20 tated in mass, the shell of one clam may serve as a scoop to disjoin the meat from a second clam; and

Fig. 11 is a vertical section of apparatus for a discontinuous process of extracting and separat- 5 ing the meats from the shells of the clams.

' My apparatus for the continuous processing of bivalves on a large scale, as shown in Figs. 1 and 2, is divided into the following major elements: a rotary screen 20, a sorting conveyor 2 l, a wash tank generally designated 22 having a scrubbing compartment 23, and a rinsing and dewatering compartment 24, a rotary cooker 25, an extractor 26, and a separator 21. Clams, designated by the letter C, are shown in the apparatus at various stages of the process.

The clams, as brought from the beach, intermixed. with a certain quantity of sand, are fed into a suitable hopper 28 having an inclined discharge spout 29 extending into rotary screen 20. Preferably, a nozzle 30, from water pipe 3| and controlled by valve 32, projects water continuously into discharge spout 29, forming a stream of sufficient velocity to carry the sand and clams in suspension.

Rotary screen 20 comprises a frusto-conical shell 33 carried by a heavy plate 34 across its smaller end, and is perforated peripherally to pass sand and small gravel but to retain the bivalves. Preferably, a second nozzle 35, supplied from pipe 3|, directs a stream of Water against the material in the rotary screen, as indicated by the drawings. A drain pan 36, having a relatively large outlet pipe 31, extends under rotary screen 20 to collect sand and water passed through the perforations. The rotary screen is mounted to the end of a shaft 38 that is integral with plate 34 and is journalled in suitable bearings 39 supported by base standards 40. Power connections are not shown.

The clams drop from rotary screen 20 onto horizontally disposed belt 4! of sorting conveyor 2|. The belt, relatively wide and preferably of a light color, is enclosed on four sides and the bottom by a suitable drain pan 42 having an outlet 43. The belt is carried by driven rollers 44 at opposite ends of the pan and the upper half of the belt may be supported between the rollers by a suitable shelf 45 attached to the drain pan by brackets 46. The belt travels at a moderate rate, permitting attendants to remove therefrom rock and other objectionable foreign matter not discarded by rotary screen 20.

The brushing compartment 23 of cleaning tank 22 is of rectangular cross-sectional configuration, and is spanned laterally by a belt 41 carried by suitable driven rollers 48 within the tank. This belt comprises an endless series of transversely disposed interlinked brushes 49 having outwardly disposed steel bristles 49w. Forward end wall 50 of the cleaning compartment is curved inward as shown to urge clams into engagement with the brushing belt, and, preferably, the bottom 5| of the brushing tank is suitably corrugated, as indicated, so that the clams are not merely brushed against the bottom of the tank, but also are turned over a number of times to be cleaned on all sides before dropping into the rinsing compartment 24.

Rinsing compartment 24 is of a configuration to encase the lower major portion of an inclined conveyor belt 52 that is equipped with flights 53 and is carried by driven rollers 54. Clams received from the brushing compartment are carried by this conveyor above the water level 55 where they are rinsed by water delivered from nozzle 56, substantially all the water draining back by the time the clams drop from the conveyor belt into cooker chute 51. Small non-fioating particles resulting from the brushing process drop through the mesh of the screen bottom 51a of the chute.

The water level in the cleaning tank is determined by a rectangular overflow outlet 58. At one side of the outlet at the front end of the brush conveyor, the cleaning tank is spanned by a baffle 59, and a similar bafile 60 at the other side of the overflow outlet spans the tank beyond the opposite end of the brushing belt and divides the brushing compartment from the rinsing compartment. Water supplied by nozzle 56 passes under baffle 60 and flows over the brushing belt to overflow 58, the two baffles serving to confine the distribution of oil and other floating foreign matter separated from the bivalves by the brushing operation.

Rotary cooker 25 has a long, horizontally disposed cylindrical shell 61 girded by two spaced channel rings 62, each of which serves as a guide rail in engagement with two suitable supporting rollers 83 mounted in brackets 64. A spiral plate 65, attached by its edge to the inner peripheral wall of the cooker, extends from the forward end of the cooker, where the end 66 of the spiral plate serves as an intake blade, to the rear end of the cooker, where the spiral plate joins an end plate 61. End plate 61 is integral with cylinder 6| and is somewhat larger than a quadrant of the cross-sectional area of the cylinder. Integral with end plate 61 and coaxial with cylinder 6|, a drive shaft 68, driven by power means not shown, slowly turns the cooker in the direction indicated by the arrow.

Cooker chute 51 terminates at its lower end in a curved flange 69 complementary to the lower portion of the forward end of cooker cylinder 6 l. By virtue of spiral plate 65, clams are continuously drawn into and moved through the rotary cooker, and finally discharged past end plate 6'! into chute 10 leading to extractor 26.

After the clams are carried past the first revolution of the spiral a small quantity of hot water may be added by means of a nozzle ll projecting into the cooker from hot water pipe line '52 and controlled by valve 13. The quantity of added water should not exceed one ounce per quart of clams and may, in fact, be omitted, inasmuch as the clams yield relatively large quantities of liquid when heated.

A series of burners 14 extending longitudinally under the cooker intermediate its ends, heatsthe clams and quickly brings the extracted liquids to a boil. As a result, the bivalve shells open on their hinges. Fig. 8 shows an unopened clam as gathered on the beach; and Fig. 9 shows the clam as opened by the cooking process,

Cylinder 6| is provided with a rectangular opening 15, covered by a screen 16 that is mounted to the cylinder by means of a suitable frame 11, so that, when the cooked mixture reaches that part of the cooker defined by the spirals on both sides of opening 15, the broth or liquid resulting from the cooking process passes through the screen into a suit-able collecting pan 18 that is positioned to register with the screened opening and is of a configuration complementary to the curvature of cylinder 5 l. From pan 18 the broth is conducted by pipe 19 to a suitable vat or container (not shown).

Extractor 26 has a cylindrical shell 8! which, as in the case of cooker 25, is girded by two spaced channel rings 82, each of which serves as a guide rail in engagement with two suitable supporting Integral with the inlet end of cylinder 8| is an end plate concentrically apertured to receive chute 10, the chute having a circular flange 86 complementary to the end plate and contiguous with the inn-er surface thereof as shown. A water pipe 81, the outer end of which is protected by I overhanging lip 88, continuously delivers water to chute ID, the water washing the clams down into the extractor. Shaft 84 extends through the bottom of chute 10, a packing gland 89 being provided in the wall of the chute.

Clams accumulating at the inlet end of the extractor gradually work towards the outlet end, being continuously agitated in transit by rotation of cylinder 8|. The extent to which the clams are tumbled or agitated in transit depends upon the rate of revolution of the cylinder, the length of the cylinder, and the inclination, if any, of the cylinder. In the form shown, the shell is horizontal and is lined with a plurality of radially inwardly extending spikes 98, which spikes, while desirable, are not necessary to successful operation.

It is obvious that cooker 25 and extractor 26 may be incorporated in a common continuous cylinder, but separate cylinders, as shown, are

preferred because different rates of speed are desirable, the extractor having the greater angular velocity.

In the tumbling operation of the extractor, the meats are disjoined from the bivalve shells, the extraction being accomplished in part by friction or abrasion, but in larger part by edgewise movements of the shells against each other, the shells acting as knives. For instance, in the course of the tumbling operation contiguous shells will be positioned as shown in Fig. 10, where the shell 9| of a bivalve generally designated 92 is positioned to scoop out the meat 93 clinging to the shell 94 of a second bivalve 95. It is contemplated that the revolving extractor 26 will provide a tumbling action of such rate and duration that practically all the bivalves, in moving through the extractor, will be subjected, sooner or later, to such or similar edgewise interaction with other bivalves. During this tumbling operation, the bivalve shells continuously gravitate to the lowermost position within the revolving cylinder 8|, while the substantial stream of water supplied by pipe 81 flows over the agitated bed of shells, serving continuously to carry off the extracted meats.

The shells and the stream of water carrying the meats are discharged onto an inclined conveyor belt 96, carried by two spaced rollers 91 in separator 21. The lower roller 91 is keyed to a freely rotatable shaft 915:. and the upper pulley is keyed to a power-driving shaft 91b, both shafts being journalled in bearings 98 mounted on separator 21. The belt carries a number of spaced transverse ribs 96a and travels upward towards extractor 26, the upper end of the belt extending under the extractor beyond the point of discharge thereof.

Associated with the separator belt is a metal casing having two parallel, irregularly shaped, side walls 99 and a rear wall I 99 spaced from the rear end of conveyor belt 99. An inclined plate I M in the casing under the upper half of belt 96, interjoins walls 99 of the casing to form therewith an inclined trough down which water from extractor 26 flows and up which conveyor belt 96 moves continuously.

When the shells, meats and water are deposited on moving belt 96, the shells are caught by ribs 96a and carried thereby up the inclined path of the belt, while the water, confined by the trough or casing carries the meats in the opposite direction over the lower end of the belt into a suitable strainer I92. The strainer is a suitable container supported by spaced rails I93, which in turn rest on floor I94 of the separator casing. The meats are caught by the strainer, and the water passes off through drainage outlets (not shown), provided in floor I94. A supplementary trough may be provided by a second inclined plate I95 interjoining walls 99 under the returning belt adjacent lower roller 91. This second trough collects water dripping from the returning belt.

Preferably, the stream of water flowing down the upper trough is augmented by a jet from a nozzle I99 that extends from water pipe I91, the jet being directed from above towards the point where material from extractor 26 is delivered to belt 99. Belt 99 passes over the upper of the two rollers 91, thereby discharging the shells S of the clams into a container I98 mounted on wheels 18a. The belt is then sprayed clean of all clinging particles of shell by a series of nozzles I99 also fed from pipe I91.

The broth drawn off through pipe 19 and the meats collected in strainer I92 may constitute separate products, or may be combined as one product, while the shells collected in container I98 constitute a by-product of the process.

The above described apparatus is designed for large-scale production, but it must be noted that essentially the same process may be carried out in a discontinuous manner on a smaller but nevertheless practical and profitable scale, by means of apparatus that will now be described.

The collected clams, after being cleaned in any practical manner, are steamed in an ordinary kettle until the shells open. Preferably, no water is added. The broth is strained OE, and then the open clams are processed in apparatus constructed as shown in Fig. 11.

The construction includes an open top cylindrical tank H9, having its bottom III set in to form a supporting skirt I I2. Water pipe I I3, controlled by valve H4, extends through skirt II2, vertically upward through bottom III, and terminates in an end piece I i 5 having a peripherally arranged series of outlets IIB. Near the bottom of the tank a drain pipe II'I, normally closed by valve I I8, is provided for occasional use.

The tank is divided horizontally by screen II 9 into an upper extractor compartment I29 and a lower water compartment I 2 I, the purpose of the latter being to provide evenly distributed fiow and pressure of water from pipe I I3 through screen II9.

Below screen II9, a thrust bearing I22 is carried by a spider I23, the spider being secured to the interior of tank I I9-by rivets I24. A vertical shaft I25 driven by means not shown, extends coaxially through screen I I9, with its lower end in bearing I22, and carries a series of radially disposed paddles I29. Preferably, the paddles are perforated and the lower paddles are aligned vertically, while the uppermost paddles I26a, are relatively short and disposed as propeller blades to urge the water upwards.

The rim of tank H9 is provided with an overflow lip I21, from which water pours into an open top cylindrical drain I28 that is attached to the side of tank II9. Drain cylinder I28 tapers at the bottom to a pipe I29 that joins drain pipe II1 outside valve II8. An open top cylindrical strainer I39 is provided at its rim with a metal ring I3 I, by means of which it may be removably suspended within drain I28, as shown.

Extracting compartment I29 is filled with the cooked clams to within approximately two inches of the overflow level. Initially, shaft I25 is revolved at a relatively rapid rate to cause violent agitation of the clams in mass by paddles I26, little or no water being forced through the mass of bivalves during this period. As described in the continuous process, agitation of the cooked bivalves in mass severs the meats from the shells. When, in the judgment of the operator, this extracting operation has been sufiiciently prolonged, the angular velocity of the paddles is reduced to a moderate rate, and valve H4 is adjusted to cause a substantial flow of water upward through screen II9 over lip I21 into strainer I 39.

The tank now functions primarily as a separator. The rate of upward flow of water, as determined by adjustment of valve H4 and the action of paddles I29w, is just sufficient to float the meats freely to the surface of the water and over lip I 21, without having the same effect on the shells. The upward movement of the water tends to work the extracted meats towards the surface, and it is important to note that the greater specific gravity of the relatively deep mass of shells as compared with that of the meats, tends to encourage the upward movement of the meats and to discourage any tendency of eddies in the water current carrying the meats downward. The overflowing water is carried away through drain pipe III, while the meats are collected by strainer I38. When practically all the meats have been collected, the empty shells are removed to be replaced by a new batch of cooked clams.

The detailed sequence of operations above given constitute a practical and efficient procedure, but it is to be understood that the process is flexible and not limited to a given order of steps. For instance, for a given batch of cooked clams, the above described operations of extraction and separation may be alternatively applied any number of times, or the batch may be subjected continuously from the start to relatively mild agitation, accompanied by flowing water, so that the operations of extraction by agitation and separation by flotation are carried out simultaneously over a relatively long period of time. The advantage of this last arrangement is that the device may be adjusted to operate without the continuous presence of an attendant.

Although, for the purposes of illustration and complete disclosure, my description has dealt with specific forms of my invention in detail, it is to be understood, nevertheless, that I reserve the right to all changes and modifications that properly come within the scope of my appended claims.

Having described my invention, I claim:

1. A method of extracting and separating meats from intermixture with opened bivalves consisting in: agitating the mixture in mass while simultaneously directing a stream of fluid therethrough with force to carry off disjoined meats without carrying off the shells.

2. A method of separating disjoined meats from opened bivalve shells consisting in: conveying the mixture of shells and meats upstream through a current of liquid, the current having force to carry off the meats Without carrying off the shells.

3. A method of processing bivalves consisting in: steaming the bivalves to open the shells; draining 01f the resultant liquor; agitating the opened bivalves in mass to disjoin the meats; stirring the mixture of shells and disjoined meats in an open vessel while simultaneously directing a current of water through the mixture and over the rim of the vessel, said current having force to carry ofi the meats; then straining the meats from the water; and adding the meats to the aforesaid liquor.

4. A method of processing bivalves consisting in: steaming the bivalves to open the shells; draining oil the resultant liquor; agitating the opened bivalves in mass to disjoin the meats; stirring the mixture of shells and disjoined meats in an open vessel while simultaneously directing a current of Water through the mixture and over the rim of the vessel, said current having force suificient to carry off the meats but less than the force necessary to carry off the shells; and straining the overflowing streams to collect the meats.

5. A method of processing bivalves comprising: cooking the bivalves to open the shells; and then disjoining the meats from the open shells by agitation in water by directing a stream of water through the intermixed meats and shells to carry the meats away from the shells.

6. A method of disjoining meats from opened bivalves comprising: tumbling the open bivalves in a cylindrical container while simultaneously directing a stream of water through the container with sufficient force to carry off the meats, but not with sufficient force to carry off the shells.

MIRIAM B. JENKINS. 

